Metro station flood highlights poor state of Helsinki municipal plumbing

Three westernmost Metro stations out of commission on Tuesday

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The extensive water damage that hit the Station Tunnel shopping area and the Metro station at Helsinki’s Central Railway Station on Sunday evening dramatically revealed the problems facing Helsinki’s municipal water system.
      “The Helsinki water network is rather old. It has been a concern of Helsinki Water. The need to make repairs is great”, says Jukka Piekkari, managing director of Helsinki Water.
      The state of the city’s plumbing was revealed about four years ago when a report on the conditions of the water network was completed.
     
Helsinki has about 1,200 kilometres of water supply pipes, of which nearly 770 kilometres was built before 1970.
      The water utility has had to triple its spending on pipe repair work to EUR 12 million a year.
      Jukka Piekkari says that EUR 15 million a year would be needed to replace all of the water mains built before 1970 within the next 20 years.
     
A rule of thumb is that a water pipeline should last for 70 years. However, it is very difficult to predict how long a pipeline will last. For instance, Helsinki has 37 kilometres of water mains over 100 years old.
      Breaks in the network occur about every other day. On Monday, there was a rupture in the Kallio district, causing hundreds of residents to be left without running water.
     
The cause of Sunday’s massive leak was a rupture in a cast iron water main 40 cm. in diameter. The pipe dates back to 1967, and on Sunday water, which was under great pressure, started gushing out of the pipe into the concrete pipeline tunnel.
      Normally the water would have filled up the concrete tunnel and flooded onto the surface through a manhole. However, there was a hole in the tunnel surrounding the pipeline, allowing the water to flood down into lounge for employees of Helsinki City Transport, and from there to the Station Tunnel.
      Monday’s big mystery was why a large hole had been cut into the pipeline tunnel.
     
An especially dangerous situation arose when the elevator shafts of the Metro fileld with water.
      “The guards left pretty fast when the elevator shaft exploded”, said fire chief Hannu Arimo. The tremendous pressure of the water sent large pieces of concrete and rock flying onto the Metro platform.
      The flow of water was stopped at 11:00 in the evening, after which the pumping of the water started. The effort was hampered by the difficulty in finding electric cords that would have been long enough to reach the platform level.
      An additional concern came from cracks that were found in the floor of the Station Tunnel. There were even worries that a floor at the upper level of the Metro station might be in danger of collapsing.
     
Fixing the damage is expected to take months, and is likely to cost millions of euros. Money for the repairs will come from the insurance fund of the City of Helsinki.
      Ticket prices for Helsinki City Transport will not have to be raised because of the accident.
     
The three westernmost stations of Helsinki’s Metro system will remain out of service through Tuesday, with trains stopping at Kaisaniemi station. A special bus line 65X has is taking passengers westward from Kaisaniemi.
      Officials hope to resume Metro service to Kamppi and Ruoholahti on Wednesday. The trains will pass the Central Railway Station without stopping during the months that repairs are being made.


Previously in HS International Edition:
  Serious water damage could close Helsinki’s busiest Metro station for months (9.11.2009)

Links:
  Helsinki City Transport
  Helsinki Water

Helsingin Sanomat